The present invention relates to an emergency release system for one or more pieces of winter sports equipment, such as skis, ski poles, snowboards, bindings and/or boots for skis or snowboards. In particular, it relates to an electrically controllable emergency release system which realizes such a separation in avalanche situations and also in other emergency situations (e.g. in case it is not possible to open the binding manually). The present invention also relates to a release method and a process for manufacturing winter sports equipment.
According to a Swiss statistic for the years 1980 to 1999 (F. Tschirky et al., Swiss Institute for Snow and Avalanche Research, CH-7260 Davos Dorf, Switzerland), the chance of survival of persons caught by avalanches is 83% in total. However, for persons who were completely buried, said chance is only 50%. There are two reasons: persons remaining at the surface can be rescued more quickly by companions and often there is a residual supply of oxygen at the surface. If the persons are deeply buried, the pressure load of the snow masses covering them often also causes injuries or kills them. Survival in an avalanche depends on several factors. For example, dead by avalanches is caused in about 70% by acute suffocation, in about 20% by a fatal trauma and in about 10% by the so-called 3-H syndrome (hypoxia, hypercapnia, hypothermia).
Thus, in an avalanche situation it is of outmost importance to remain as long as possible (at best completely) at the surface of the snow. A recommendation for an avalanche situation therefore is to keep oneself at the surface by making swimming movements (flowing snow masses tend to have the characteristics of a fluid). For, firstly, effective swimming movements being at all possible and, secondly, an anchoring effect generated by skis and ski poles or by the snowboard not being caused, it is urgently necessary to separate person and equipment from one another. Caused by the so-called inverse segregation effect, large parts (such as the body of a skier) are moved rather to the surface. An anchorage caused, e.g., by the ski with relatively deep snow layers is disadvantageous to this effect. The versed sportsman/sportswoman can first try to escape the snow masses by a rapid schuss. As soon as he/she fails, however, he/she must be separated from his/her equipment as quickly as possible upon his/her “release command”. In such situations, it is as a rule impossible to separate oneself from the ski by releasing the ski binding. Reason: in the flowing medium “avalanche” there are at first only relatively small forces which cannot release the force- or moment-controlled ski bindings that are common nowadays. When the snow masses have compacted such that the resulting forces are sufficient for releasing the binding, it is in most cases too late for being freed.
For preventing the greatest risk—death by suffocation—it is tried, i.a., to reduce the degree of burial by means of additional safety equipment, such as the avalanche airbag (comprising two folded plastic balloons which are integrated at the sides of a backpack and, after pulling a trigger line, are inflated within 2 to 3 seconds by 150 liters of an nitrogen/air mixture; see also www.abs-lawinenairbag.de) or the life vest Avagear™ (here the balloons surround the shoulder and neck region; see also www.avagear.net). The effectiveness of both devices is based on the principle of the above-mentioned inverse segregation in granular flows.
On the basis of first field tests and evaluations of accident data by the Swiss Institute for Snow and Avalanche Research it is assumed that airbag users have all in all a lower risk to die in avalanche accidents. Nevertheless, in particular the anchoring effect caused by skis and ski poles can be disadvantageous to the inverse segregation effect and prevent the skier having the accident from making swimming movements in order to remain on top of the snow.
It is known to integrate sensors and electronic equipments into releasable alpine bindings in order to avoid mechanical overloads on bones or ligaments. Additionally using electrically ignitable explosive charges for releasing a safety binding for skis is known, i.a., from the following documents: published German patent application DE 2 416 424 teaches a safety fastener, in particular a safety binding for skis, with automatic opening upon the occurrence or under the action of predetermined critical outside influences. The unlocking means can comprise a pyrotechnical charge and means for igniting this charge.
Published German patent application DE 25 19 544 relates to a safety binding for skis, in particular to a device for electrically releasing a ski binding. The control means can comprise an electrically ignited cartridge or an electrically controlled explosive means.
German patent DE 27 17 624 claims an explosive charge release means for a latching means, in particular for a safety binding for skis, comprising a release member acting on the latch of the latching means, a storage for a plurality of cartridges comprising the explosive charges, and a reloading means for successively moving the cartridges into an operating position.
German patent DE 44 46 260 relates to an electronically controlled safety binding for skis and snowboards, in which the forces are measured electronically by means of piezo crystals and the binding is opened quickly by means of an explosive or propelling charge if forces occur which are dangerous to the skier or snowboarder. Moreover, the binding comprises springs for being released mechanically.
A further pyrotechnical approach is disclosed in published German patent application DE 10 2007 001 599, which provides a safety binding, ski binding, bindings and their foundation, characterized in that the skier can control, by means of radio signals in a wireless or wired manner, pyrotechnical propelling charges, telescope-like cartridges or relatively large explosive charges with great explosive power (up to about 6 g TNT) which act on the binding or its foundation, in order to free himself/herself from the binding of the ski by means of ignition.
Ski binding systems that can be released on purpose by the skier are known, i.a., from the following documents: U.S. Pat. No. 3,246,907 relates to a magnetic ski binding which can be released by the skier by applying a switch on a ski pole. The thus generated signal is transmitted by electrical conductors passing from the ski pole through the clothing and the ski boots to the bindings.
German patent DE 16 03 001 describes a ski binding comprising a release device that can be arbitrarily controlled by the skier by remote control, wherein the remotely controlled means consists of a battery-powered receiver which can be influenced by a battery-powered transmitter worn by the skier.
Published German patent application DE 22 19 415 discloses a ski binding in which a sole holder is held in the use position by means of a releasable locking means, wherein the locking means can be unlocked by means of an electric motor and the electric motor can be remotely controlled by a hand switch or a load sensor.
German patent DE 24 02 684 describes a release device for ski bindings which comprises a mechanical clamping device for clamping the boot of a skier to a ski, a transmitter which is attached to a ski pole and can be controlled by the skier, and a receiver which is attached to the ski and connected with the clamping device.
German patent DE 38 08 643 relates to an automatically releasable ski binding unit with interconnected front and heel parts, a mechanical boot holding system, an electronic control and a release system for the ski boot. The electronic release can be remotely controlled, which means that for leaving the ski binding it is only necessary to apply a remote-control element worn on the body.
European patent EP 0 228 599 discloses a release device for a locking mechanism of a jaw assembly of a ski binding, wherein the release device comprises a transmitter housed in a ski pole provided with a grip handle, a manual actuator disposed on the free end face of said grip handle of said ski pole so as to be immediately accessible from outside, and a switch operable by said manual actuator, and wherein the locking mechanism of said jaw assembly is releasable under the control of a receiver associated to said jaw assembly and selectively controllable by said transmitter. The manual actuator is arranged so as to be protected from involuntary actuation.
Since the trend in the touring and free-riding sector led to an increase in the market of 102% in the season 2003/2004—an Austrian producer alone registered an increase in the amount of products sold by almost 60% in the product segment of touring or hiking skis in the season 2003/2004—it can be assumed that there is a considerable demand for improved safety concepts.
It is the object of the present invention to provide an improved safety concept for winter sports, in particular for alpine and tour skiing, snowboards and the like.